Die casting (331523) uses high-pressure injection of molten metal into hardened steel dies, producing high-volume, tight-tolerance parts — automotive transmission housings, consumer electronics enclosures, and hardware components — predominantly in zinc and aluminum alloys. Other nonferrous casting methods (331529) cover sand casting, permanent mold, and investment casting, which are better suited to lower volumes, larger parts, or alloys (such as bronze or magnesium) that are less compatible with high-pressure dies. Trade patterns differ accordingly: die castings are often sourced from high-volume, low-cost manufacturing regions, while specialty nonferrous castings may be sourced for alloy or certification reasons.

The use of secondary (recycled) metal in a casting does not change its HTS classification, which is based on the finished article's composition and form rather than feedstock origin. However, recycled content may affect material certifications required by the buyer (e.g., aerospace or automotive quality standards that specify virgin alloy or controlled chemistry), and customs valuation is based on the transaction value of the finished casting, not the scrap value of its inputs.